I just talked to a mom today from this forum who's little girl (9 yrs old?) has been taking Algin and she has improved a lot (behavior-wise). Her daughter's mercury exposure was most likely from vaccinations, but possibly also from environmental sources (the little girl was adopted from an Asian country so it's hard to know for sure).

Besides Algin, I would suggest at least 3 to 4 grams of a good quality Vitamin C with bioflavonoids (which occur with vitamin C naturally). Just make sure there's no added sugar, etc. I use and recommend NSP's Vitamin C, Citrus Bioflavonoids

As far as herbs for general good health, there's Alfalfa and Bee Pollen, which are both full of nutrients. Another products that has worked great for my nephew and other children I know is Elderberry Plus to help keep their immune systems healthy (no more runny noses, coughs, colds, etc.).

However, it's amazing what a difference diet can make in kids. Just getting them off sugar (even too much fruit sugar can have a negative effect) can make a world of difference in their personalities, attention spans, behavior, etc.